# Conflicts: # apps/web/tests/markdown-images.e2e.ts # docs/cordis-catalog/services.md # docs/core-data-structures/session.i18n.yaml # docs/event-producer-consumer.md # examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl # packages/compact/compact-basic/tests/compact-basic.spec.ts # packages/context/time-context/tests/invariant.spec.ts # packages/context/time-context/tests/time-context.spec.ts # packages/core/agent-loop/src/invariant.ts # packages/core/agent-loop/tests/contract-regressions.spec.ts # packages/core/agent-loop/tests/request-reconstruction.spec.ts # packages/core/agent/tests/agent.spec.ts # packages/core/session/README.i18n.yaml # packages/core/session/src/index.ts # packages/core/session/tests/derived-cache.spec.ts # packages/core/session/tests/request-header.spec.ts # packages/core/session/tests/session.spec.ts # packages/core/session/tests/surface.spec.ts # packages/fs/tool-str-replace-editor/tests/tools.spec.ts # packages/goal/goal/tests/goal.spec.ts # packages/plan/plan-mode/tests/plan-mode.spec.ts # packages/pty/pty-local/tests/index.spec.ts # packages/pty/pty-local/tests/local.spec.ts # packages/pty/pty/tests/service.spec.ts # packages/pty/tool-bash-persistent/tests/loader-composition.spec.ts # packages/pty/tool-bash-persistent/tests/tools.spec.ts # packages/pty/tool-pty/tests/loader-composition.spec.ts # packages/pty/tool-pty/tests/tools.spec.ts # packages/session-title/session-title-all-messages-llm/tests/provider.spec.ts # packages/tasks/tasks-local/tests/tasks.spec.ts # packages/ui/user-approval/tests/approval.spec.ts
subagent/ — subagent capability family
English | 中文
The subagent seam: an agent delegating work to a child agent. Like the bash and llm families this is a capability seam (see capability seams) — but with one defining difference: multiple provider implementations coexist in one context, registered by name, rather than the single-implementation bash shape. The registry mirrors the LLM adapter registry.
| Package | Role | ctx key |
|---|---|---|
subagent/ |
Subagent service: named-provider registry, vocabulary, durable descriptor, and continuable-child orchestration | ctx.subagents |
subagent-inprocess/ |
Shared in-process run driver (no provider; one cleanup effect per run) | — |
subagent-spawn/ |
In-process backend: a fresh child agent, with cold resume | (registers on ctx.subagents) |
subagent-fork/ |
In-process backend: a child seeded with the parent's completed-turn prefix, with cold resume | (registers on ctx.subagents) |
subagent-acp/ |
Out-of-process backend: a child agent in a spawned subprocess, driven over ACP (one-shot) | (registers on ctx.subagents) |
subagent-dsh-sdk/ |
Out-of-process backend: a child harness runtime in a spawned subprocess, driven over stdio JSON-RPC through the TypeScript SDK client | (registers on ctx.subagents) |
tool-subagent/ |
Model-facing subagent delegation tool over ctx.subagents |
(registers on ctx.tools) |
tool-subagent-control/ |
The optional, globally named send_message and list_agents tools over ctx.subagents |
(registers on ctx.tools) |
tool-subagent-report/ |
Child-scoped report return channel for continuable in-process children |
(registers in each child scope) |
The interface and continuation orchestration live at subagent/subagent/. One-shot provider start dispatch stays independent of persistence; an internal continuation manager owns each durable continuable child as one Session plus at most one process-local Activation, binding no Task, and exists only while the Agent service is present, resolving persistence per continuation operation. The in-process subagent-spawn / subagent-fork backends share the subagent-inprocess driver (a library with no provider of its own — both depend on it, neither on the other), and the out-of-process subagent-acp / subagent-dsh-sdk backends spawn their children through the subprocess/ seam (the shared credential scrub, tree-scoped teardown, and dispose ladder). Tests replace only the child boundary with package-local fixtures.
The design rationale: .agents/notes/implemented/feature/2026-06-21-subagent-capability-seam.md, .agents/notes/implemented/feature/2026-07-21-continuable-background-subagents.md, and .agents/notes/implemented/simplification/2026-07-26-merge-subagent-control-service.md.